I don't follow. Even looking painfully close to my retina displays the picture still looks great. There is no point where suddenly skin pores become noticeable

I don't follow. Even looking painfully close to my retina displays the picture still looks great. There is no point where suddenly skin pores become noticeable when they weren't previously. If you see skin pores in a movie then that's the fault of the makeup department--I recall reading early HDTV productions struggled with this. Rather, I think the reason why theatres don't benefit from 8k is that from a certain distance increased resolution doesn't have a benefit. E.g. If you ever get close to a billboard you may notice that the resolution of the ad is quite poor, but from street level it looks perfectly fine. We aren sitting much farther than 10' from the theatre screen, so more resolution won't be noticeable given the distance from the screen for most of the audience.